Monday, January 17, 2011

How to choose the wood stain

Stain is one of the finishing materials that is very important in the finishing industry. Stain is the finishing material used to form the color, while a finishing process is always associated with the color and coloring process. Therefore, the proper selection of stain and its applications is very important in the finishing industry. At this time actually the finishing industry has provided material to make various types of stains, each of which has unique properties and has complete color catalog. Thus, the finishing peoples just need to choose a certain type of stain and color according to the finishing required. The finishing peoples does not need to make the stain as in the past. However, the finishing players has to recognize every type of stain and its properties to be able to choose the stain.

Here are some aspects need to be consider when we want to meet the best suit stain in a finishing process.

The quality and specification of the finishing required.

The finishing quality and requirement should be considered as the first consideration in the stain selection, since it will limit the chemical of the material that can be used. It also according with the purpose of the furniture product. for example the finishing for the outdoor uses, should use the stain that can withstand the u.v. light, the baby finishing for baby furniture should be free toxic and safe for baby health, etc. The stain as the finishing material used is also limited with the finishing requirement. Theoretically we can make any color of the stain, but we have to make sure that we use the proper chemical.

The color and looked of the finishing

The type of stain used and the way application will determine looked of the finishing. Now there are many stain type are available. The stain type is determined by the ingredient in the mixture; the pigment, binder and the solvents. Each type of stain will give a special finishing looked resulted. There are two type of pigment the inorganic and the organic stain that be used in the stain. Generally the organic stain is more clear and bright (see previous article about the stain in the wood finishing). The inorganic pigment stain more suited to a finishing with bright colors, whereas inorganic stain more suited for more close and dull color.

The other ingredient in the stain are the binder and the solvents. They will determine the character of the stain such as the drying time, the application method, the compatibility with the clear coating used, etc. The stain used in a finishing process also should according with the clear coating used in the finishing process. Some reaction cured clear coating such as P.U., U.V. , A.C., etc. may need some special stain since the chemical reaction in its drying process. Then the stain selection should be in accordance with the finish looked. There are many stain type that will give different finish effect. Simply the longer time stain to dry, the more stain wet, fill and color the pores and grain. The longer time dry stain will more enhance and show the grain and pores pattern in the wood. While the fast dry stain is tend to make more flat color finish.

The stain used is also have to follow the color of the finishing. The stain color should be according with the final color needed and the wood base color. To help find the right color of the stain we can use the triangle color diagram or the color wheel diagram.

The finishing facilities and equipment available

The stain selected for a process of finishing must be applicable in the finishing process. Therefore, the selection of stain must conform to the facilities and equipment available. The stain used must be easy to be applied according to the condition where the finishing is done. In some cases we may need to adjust the stain to simply the finishing process.

The properties of wood.

Wood is a substrate with wide range characters and properties. Wood characters can vary depending on the type of wood and the place where he grew up. There are 2 wood characters that need to be considered in the selection of stain, the base color and porosity. The basic color of the wood will mix with the stain color to form the desired final finishing color. Since that the stain used must conform with the basic color of wood to produce the desired final color. (Find it more in our previous article: how to make color in wood finishing) The other important wood properties is the porosity of wood. Wood with a high porosity will tend to absorb more stain, It will tend to produce dark color than the wood that has low porosity. Some types of wood and even has high tendency to the result in blotchy color, especially when the long time drying stain is used. So to stain the high porosity wood , the slow dry stain should be avoided. The fast dry stain or toner (stain with little clear coating in the mixture) with spray application is better option to reduce the risk of blotchy on the soft wood.

Always do a test with a small application before do application on big product.

Each stain may produce different effects in the different finishing process. Before apply stain in a big volume finishing process, some experiment to apply the stain on small panel is highly recommended. Apply the stain in a small panel and evaluate the result before do the staining process for the big volume job. A step panel is very important to be made in the beginning of finishing project.

Yes we can increase the solid content of the NC, but it will also increase the viscosity and make it cannot well applied with the spray gun.If you want to make flat finish with NC, then you need a flat surface and the perfect surface in your unfinished substrate.